A&P Chapter #23 - 1

___ material enters through the mouth

___ takes place after ingestion, via action of the tongue, teeth/jaw motions, muscular movement of the digestive tract (chewing, segmentation, churning)

___ swallowing, peristalisis

___ is the actual breakdown of food, into molecules that can be absorbed by the digestive epithelium

___ requires acids, enzymes, buffers for reactions to occur, process of SECRETION supplies these essentials

___ : movement of substances across digestive epithelium to interstitial space (includes organic molecules, electrolytes (ions), vitamins, water)

___ : dehydrate indigestible material

___ : discharge of fecal material

___ exists as a 3-Dimensional structure, functions to increase surface area available for absorption.

___ Cells in areas where mechanical stresses are greatest Ex.) oral cavity, pharynx, esophagus, rectum, anus.

___ Cells in the remainder of the GI tract, where secretory cells are common.

___ Two-layered smooth muscle structure (one circular arrangement next to sm. muscle in longitudinal arrangement) Will alter lumen shape, move folds.

___ A connective tissue layer (+ blood vessels, nerves, lymphatic tissue, smooth muscle)

EPITHELIUM + L.PROPRIA + MUSCLARIS MUCOSAE = ___

___ A connective tissue layer (second), same composition as the lamina propria

Submucosa surrounds muscularis mucosae that may contain ___ (buffers, enzymes, acids)

Submucosa contains sensory nerve fibers = ___(PNS and SNS fibers)

___ smooth muscle structure circular inner layer and longitudinal outer layer

___ Role in moving bolus of food through GI tract

Muscularis Externa movements are controlled by ___ that lies between the two sm. muscle layers.(parasympathetic will increase muscle activity/tone, while the sympathetic input will inhibit contraction, relaxation results)

___ Loose connective tissue layer surrounds mus. externa.

@ oral cavity/esophogus/rectum the adventitia is attached to adjacent structures via dense ___

@ areas of GI tract within the peritoneal cavity, the adventitia is covered by the ___

___ Serous membranes, secrete serous fluid(lubricates, decrease friction), A cavity exists between 2

Peritoneum on organ ___

___ lines peritoneal cavity

Folded extensions of the visceral and parietal peritoneum.

Non Striated (no sarcomeres),Spindle Shape cell,Single Nucleus, Actin & Myosin protein filaments exists.

Initiation of contraction begins as the lekage of Ca2 into ___

MLCK

Once an interaction between actin & myosin occurs sliding results and cell shortens causing ___

___ of certain muscularis regions of the GI tract will undergo spontaneous depolarization, leading to contraction

___ will result from local stimuli, i.e.sensory receptors in the walls of the tract trigger a local contraction (region of a few cm)

Contractions may be initiated by fibers of the

GI tract Contraction - effects of Parasympathetic activity ___

GI tract Contraction - effects of Sympathetic activity ___

The movement of materials from one part of the GI tract to another via muscularis externa contractions ___

The contractions occur in a specific order ___

The sm.intestine exhibit ___ movement